Refractory slurry of reducing carbon pickup in lost foam casting, foam pattern and processes for manufacturing and using the same

Abstract

Refractory slurry for use in coating a foam cluster to provide a foam pattern for lost foam casting is provided. The slurry includes a catalyst capable of catalyzing reactions for vaporizing the foam cluster. A foam pattern with a refractory coating including the catalyst and processes for preparing the foam pattern and using the foam pattern are also provided.

What is claimed is: 
     
         1 . A foam pattern for lost foam casting, the foam pattern comprising:
 a foam cluster; and   a refractory coating coated on the foam cluster, wherein the refractory coating comprises a catalyst capable of catalyzing reactions for vaporizing the foam cluster, the catalyst comprising at least a carnegieite-like material of formula (Na 2 O) x Na 2 [Al 2 Si 2 O 8 ] or a perovskite material of formula A a B b C c D d O 3-δ , wherein:
 0<x≦1, 0<a<1.2, 0≦b≦1.2, 0.9<a+b≦1.2, 0<c<1.2, 0≦d≦1.2, 0.9<c+d≦1.2, −0.5<δ<0.5; 
 A is selected from calcium (Ca), strontium (Sr), barium (Ba), and any combination thereof; 
 B is selected from lithium (Li), sodium (Na), potassium (K), rubidium (Rb) and any combination thereof; 
 C is selected from cerium (Ce), zirconium (Zr), antimony (Sb), praseodymium (Pr), titanium (Ti), chromium (Cr), manganese (Mn), ferrum (Fe), cobalt (Co), nickel (Ni), gallium (Ga), tin (Sn), terbium (Tb) and any combination thereof; and 
 D is selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), ebium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), ferrum (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), gallium (Ga), indium (In), tin (Sn), antimony (Sb) and any combination thereof. 
   
     
     
         2 . The foam pattern of  claim 1 , wherein the perovskite material is selected from the group consisting of doped LaCrO 3 , doped LaMnO 3 , BaCeO 3 , BaZrO 3 , BaCe y Zr (1-y) O 3 , BaCe y Y (1-y) O 3  and combinations thereof, wherein 0≦y≦1. 
     
     
         3 . The foam pattern of  claim 2 , wherein the perovskite material is BaCe y Zr (1-y) O 3 , wherein 0≦y≦1. 
     
     
         4 . The foam pattern of  claim 1 , wherein the refractory coating comprises about 1-80% by weight of the catalyst. 
     
     
         5 . The foam pattern of  claim 4 , wherein the refractory coating comprises about 50-80% by weight of the catalyst. 
     
     
         6 . The foam pattern of  claim 4 , wherein the refractory coating comprises about 1-30% by weight of the catalyst and about 30-60% by weight of a refractory compound selected from the group consisting of alumina, zirconia, silica, chromite, alumina-silicates, and combinations thereof. 
     
     
         7 . The foam pattern of  claim 5 , wherein the refractory coating further comprises a binder, a surfactant, a thixotropic agent and a dispersant. 
     
     
         8 . The foam pattern of  claim 7 , wherein the binder comprises clay and carboxymethyl cellulose (CMC) gum. 
     
     
         9 . A process for making a foam pattern for lost foam casting, the process comprising:
 preparing a foam cluster; and   coating the foam cluster with a refractory coating comprising a catalyst capable of catalyzing reactions for vaporizing the foam cluster, the catalyst comprising at least a carnegieite-like material of formula (Na 2 O) x Na 2 [Al 2 Si 2 O 8 ] or a perovskite material of formula A a B b C c D d O 3-δ , wherein:
 0<x≦1, 0<a<1.2, 0≦b≦1.2, 0.9<a+b≦1.2, 0<c<1.2, 0≦d≦1.2, 0.9<c+d≦1.2, −0.5<δ<0.5; 
 A is selected from calcium (Ca), strontium (Sr), barium (Ba), and any combination thereof; 
 B is selected from lithium (Li), sodium (Na), potassium (K), rubidium (Rb) and any combination thereof; 
 C is selected from cerium (Ce), zirconium (Zr), antimony (Sb), praseodymium (Pr), titanium (Ti), chromium (Cr), manganese (Mn), ferrum (Fe), cobalt (Co), nickel (Ni), gallium (Ga), tin (Sn), terbium (Tb) and any combination thereof; and 
 D is selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), ebium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), ferrum (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), gallium (Ga), indium (In), tin (Sn), antimony (Sb) and any combination thereof. 
   
     
     
         10 . The process of  claim 9 , wherein the perovskite material is selected from the group consisting of doped LaCrO 3 , doped LaMnO 3 , BaCeO 3 , BaZrO 3 , BaCe y Zr (1-y) O 3 , BaCe y Y (1-y) O 3  and combinations thereof, wherein 0≦y≦1. 
     
     
         11 . The process of  claim 9 , wherein the perovskite material is BaCe y Zr (1-y) O 3 , wherein 0≦y≦1. 
     
     
         12 . The process of  claim 9 , wherein the refractory coating is coated onto the foam cluster by a process comprising the following steps:
 preparing refractory slurry containing the catalyst;   applying the slurry to the foam cluster to form a slurry coating on the foam cluster; and   drying the slurry coating.   
     
     
         13 . Refractory slurry for use in coating a foam cluster to provide a foam pattern for lost foam casting, the refractory slurry comprising:
 a catalyst capable of catalyzing reactions for vaporizing the foam cluster, the catalyst comprising at least a carnegieite-like material of formula (Na 2 O) x Na 2 [Al 2 Si 2 O 8 ] or a perovskite material of formula A a B b C c D d O 3-δ , wherein:
 0<x≦1, 0<a<1.2, 0≦b≦1.2, 0.9<a+b≦1.2, 0<c<1.2, 0≦d≦1.2, 0.9<c+d≦1.2, −0.5<δ<0.5; 
 A is selected from calcium (Ca), strontium (Sr), barium (Ba), and any combination thereof; 
 B is selected from lithium (Li), sodium (Na), potassium (K), rubidium (Rb) and any combination thereof; 
 C is selected from cerium (Ce), zirconium (Zr), antimony (Sb), praseodymium (Pr), titanium (Ti), chromium (Cr), manganese (Mn), ferrum (Fe), cobalt (Co), nickel (Ni), gallium (Ga), tin (Sn), terbium (Tb) and any combination thereof; and 
 D is selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), ebium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), ferrum (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), gallium (Ga), indium (In), tin (Sn), antimony (Sb) and any combination thereof. 
   
     
     
         14 . The refractory slurry of  claim 13 , wherein the catalyst is about 50-80% by weight. 
     
     
         15 . The refractory slurry of  claim 13 , wherein the catalyst is about 1-30% by weight. 
     
     
         16 . The refractory slurry of  claim 15 , further comprising about 30-60% by weight of a refractory compound selected from the group consisting of zirconia, silica, chromite, alumina-silicates, and combinations thereof. 
     
     
         17 . The refractory slurry of  claim 14 , further comprising a binder, a surfactant, a thixotropic agent and a dispersant. 
     
     
         18 . The refractory slurry of  claim 17 , wherein the binder comprises clay and carboxymethyl cellulose (CMC) gum. 
     
     
         19 . A lost foam casting method, comprising:
 providing a foam pattern comprising a foam cluster and a refractory coating coated on the foam cluster, wherein the refractory coating comprises a catalyst capable of catalyzing reactions for vaporizing the foam cluster, the catalyst comprising at least a carnegieite-like material of formula (Na 2 O) x Na 2 [Al 2 Si 2 O 8 ] or a perovskite material of formula A a B b C c D d O 3-δ , wherein:
 0<x≦1, 0<a<1.2, 0≦b≦1.2, 0.9<a+b≦1.2, 0<c<1.2, 0≦d≦1.2, 0.9<c+d≦1.2, −0.5<δ<0.5; 
 A is selected from calcium (Ca), strontium (Sr), barium (Ba), and any combination thereof; 
 B is selected from lithium (Li), sodium (Na), potassium (K), rubidium (Rb) and any combination thereof; 
 C is selected from cerium (Ce), zirconium (Zr), antimony (Sb), praseodymium (Pr), titanium (Ti), chromium (Cr), manganese (Mn), ferrum (Fe), cobalt (Co), nickel (Ni), gallium (Ga), tin (Sn), terbium (Tb) and any combination thereof; and 
 D is selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), ebium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), ferrum (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), gallium (Ga), indium (In), tin (Sn), antimony (Sb) and any combination thereof; 
   placing the pattern in a bed of sand to form a mold about the foam pattern;   introducing molten metal into the mold to vaporize and displace the foam cluster of foam pattern and form a casting that replicates the shape of the foam pattern, while catalyzing the reactions for vaporizing the foam cluster around the refractory coating; and   removing the sand from around the casting.   
     
     
         20 . The method of  claim 19 , further comprising removing the refractory coating from around the casting.